Problem: Simplify to lowest terms. $\dfrac{15}{50}$
Answer: What is the greatest common factor (GCD) of 15 and 50? $15 = 3\cdot5$ $50 = 2\cdot5\cdot5$ $\mbox{GCD}(15, 50) = 5$ $\dfrac{15}{50} = \dfrac{3 \cdot 5}{ 10\cdot 5}$ $\hphantom{\dfrac{15}{50}} = \dfrac{3}{10} \cdot \dfrac{5}{5}$ $\hphantom{\dfrac{15}{50}} = \dfrac{3}{10} \cdot 1$ $\hphantom{\dfrac{15}{50}} = \dfrac{3}{10}$